Leader pin



Patented Sept. 12, I933 unirsofsr-A'res PATENT orries 7 LEADER PIN v Emil A. Baumbach, Chicago, 111;, assignor to Advance Die Set Corporation, Chicago, 111., a corporation of lllinois Application March 2,1931- Serial No. 519,461

*7 Claims. (oi. 287-20) i My invention relates to leaderpinaandmore particularly to leader pins arranged to befsecured in a die shoe to co-operate with, a punch holder for the purpose of accurately aligning .a punch with a die. Y

This invention contemplates a removable lead er pin wherein is :provided a construction by which the pin maybe firmly and securely positioned' in an opening in the die shoe and whichis operable to allow the insertion or removal of thepin at anytime.

A desirable feature. is the provision of means entirely contained within the contour of the pin whereby the leader pin maybe readily removed and replaced and will always be accurately positioned relative to the openings in the punch holder. a 1

-It is also an object to provide a securing mechanism enclosed within the contour. of the pin and win which the. engaging means provides a cover completely. enclosing theoperating mechanism and preventing dust and dirt from entering therein. x

Further objects willbe apparent from the specification and drawing, in which drawing;

Figure 1. is a perspective view of a punch holde. er and die shoe incorporating an embodimentoi my invention; a I

Fig. 2 is a sideelevational View of one of the leader pins in position in the die shoe, a portion of the leader pin and the die shoe being broken away for purposes of illustration;

Fig. 3 is a transverse sectional view through the leader pin and die shoe and taken on a line corresponding to line 33 of Fig. 2, with the clamping ring turned slightly from the position of Fig. 2 and shown in section;

Fig. 4 is a detailed sectional view through the leader pin and taken on a line corresponding to line 44 of Fig. 2; and

Fig. 5 is a detailed sectionalfragmentary View of a portion of the retaining and clamping ring illustrating the means for preventing rotation of.

the ring.

Referring to the drawingthe embodiment illustrated comprises a dieshoe 1, in cooperative relation with a suitable die and a punch holder 2 for supporting a punch which latter cooperates with a suitable die.

A pair of leader pins 3, removably secured in the die shoe, are extended through suitable guide holes 4 in the punch holder for the purpose of accurately aligning the punch and die.

The punch holder and die shoe may be of any being such that the pins can be readily inserted and removed, but yet hold the pins firmly against any lateral movement in the openings. In order to secure a pin in the opening, a plurality of gripping pins 6 are slidably mounted in radially disposed openings '7 in the lower end oi the leader pin 3, and an adjusting screw 8, having a tapered conical end 9, is mountedin a threaded axial opening 10. The tapered conical end 9 is arranged to engage the spherical inner ends of the gripping pins- 6 so that when the screw 8 is operated the conical portion 9 will force the gripping pins outwardly. A resilient split clamping ring ll is arranged in a slot '12-in a position to retain the gripping pins 6 in assembled position when the leader pin is removed from the die holder. .The ring 11 provides a suitable clamp-. ing means ior engaging the die shoe and a groove. 13 is provided in the die shoe to receive the ring llfwhen itis pressed outwardly by the gripping pins 6 as they are moved by the adjusting screw 8. The ring 11 is preferably of sheet-metal and of curved cross-sectional contour, the outer con tour conforming in'shape to the groove 13 and the inner contour conforming substantially to the curvature of the outer ends of the pins 6.

A hexagonal wrench 14 is arranged to be inserted in the hexagonal opening 15 for the purpose of turning the adjusting screw 8 for locking and unlocking the leader pin in the die shoe. When the leader pin is inserted in the opening 5 in the die shoe the screw 8 will'be in a lowered position, and the gripping pins will be pushed inwardly by the ring 11 and the ring will normally be somewhat below the surface of the leader pin. In order to lock the pin in position in the die shoe, the screw 8 is operated to push the gripping pins 6 outwardly and the ring 11 will be forced into the groove 13, and the leader pin will thereby be held rigidly in position. The ends of the split ring 11 are turned inwardly at 16 thereby preventing the ring from rotating to a position where oneof the gripping pins may enter slot 17 through radial openings 7.

In order to remove the leader pin, it is only necessary to turn the screw 8 in a direction to release the gripping pins 6 whereby the ring 11 will automatically be released from the groove 13. It will be seen that this construction is such that the leader pins will be firmly held in the die shoe without any chance of lateral or longitudinal movement and that they may be easily re moved and replaced when desired.

It will be noted that the ring 11 substantially fills the slot 12 and completely covers the radial openings when the pin is removed from the die shoe thereby preventing dirt from entering therein; and providing a device which may be conveniently used or stored under the usual machine shop conditions without injury.

While I have shown but one form of my invention, it will be understood that it may be embodied in other forms and I desire to be limited only by the prior art and the appended claims.

I claim:

1. A leader pin for insertion in an opening in a sup-port, a plurality of radially disposed later ally movable members in said pin, movable means normally within the cylindrical surface of said pin for retaining said movable members normally within the contour of said pinand adjustable means for causing said retaining means to engage the walls of said support opening.

2. A leader pin for insertion in an opening in 3. A combined retainer and clamping ring for,

a pin adjusting means of the character described comprising a resilient sheet metal split'ring of concavoconvex cross-sectional contour, and inwardly extending portions 011 the ends of said ring for engaging theadjusting means to prevent rotation of the ring.

4. In a device for securing guide pins in a support the combination with a support having a cylindrical hole therein and a lateral groove in the wall of said hole, a snugly fitting pin arranged to be inserted in said hole, a lateral groove in said pin, a ring in said pingroove conforming in cross sectional contourto the shape of said support groove and arranged to be expanded in 'in said opening and having a lateral groove for alignment with said support groove, a resilient member in said pin groove and normally below the cylindrical surface of said pin, movable members radially spaced in said pin and engaging the inner surface of said resilient member, and means within said pin and cooperating with said movable members to releasably force said resilient member beyond the surface of said leader pin and into frictional locking engagement with said support groove.

6. A device of the character described compris ing a support having an opening therein for a leader pin and an annular groove arcuate in cross section in the wall of said opening, a snugly fitting pin for insertion in said opening and having a lateral groove of substantially the same width as the support groove and arranged for alignment therewith, a resilient member in said pin groove and. normally below the cylindrical surface of said pin and having a cross sectional contour conforming substantially to the contour of said support groove, movable members radially disposed in said pin and engaging the inner surface of said resilient member, and means within said pin and cooperating with said movable members to releasably force said resilient member be-' yond the surface of said leader pin and into fric- 110 tional locking engagement. with said support groove.

7. A leader pin for insertion in a snugly fitting opening in a support, a plurality of radially disposed laterally movable members in said pin, re-. 115 silient means normally within the contour of said pin and completely enclosing said radial members to prevent the access of dirt thereto, and adjustable means in said pin and cooperating with said radial members to move said resilient means 120 beyond the contour of said pin and into locking engagement with the walls of said opening.

EMIL A. BAUMBACH. 

